namespace ZB.MOM.WW.Audit.Tests;

public class TruncatingAuditRedactorTests
{
    private static AuditEvent Evt(string? details, string? target = null) => new()
    {
        EventId = Guid.NewGuid(), OccurredAtUtc = DateTimeOffset.UtcNow,
        Actor = "a", Action = "x", Outcome = AuditOutcome.Success,
        DetailsJson = details, Target = target,
    };

    [Fact]
    public void Short_values_pass_through_unchanged()
    {
        var r = new TruncatingAuditRedactor(new() { MaxDetailsJsonLength = 100 });
        var evt = Evt("small");
        Assert.Equal("small", r.Apply(evt).DetailsJson);
    }

    [Fact]
    public void Oversized_details_are_truncated_with_marker()
    {
        var opts = new TruncatingAuditRedactorOptions { MaxDetailsJsonLength = 10, TruncationMarker = "~" };
        var r = new TruncatingAuditRedactor(opts);
        var result = r.Apply(Evt(new string('x', 50)));
        Assert.Equal(10, result.DetailsJson!.Length);
        Assert.EndsWith("~", result.DetailsJson);
    }

    [Fact]
    public void Oversized_target_is_truncated()
    {
        var r = new TruncatingAuditRedactor(new() { MaxTargetLength = 5, TruncationMarker = "" });
        var result = r.Apply(Evt(null, target: "abcdefghij"));
        Assert.Equal(5, result.Target!.Length);
    }

    [Fact]
    public void Null_fields_are_left_null()
    {
        var r = new TruncatingAuditRedactor();
        var result = r.Apply(Evt(null));
        Assert.Null(result.DetailsJson);
        Assert.Null(result.Target);
    }

    [Fact]
    public void Marker_longer_than_max_clips_the_marker_itself()
    {
        // Misconfiguration: marker longer than the cap. Must not throw; clips to the first max chars.
        var opts = new TruncatingAuditRedactorOptions { MaxDetailsJsonLength = 3, TruncationMarker = "…[truncated]" };
        var r = new TruncatingAuditRedactor(opts);
        var result = r.Apply(Evt(new string('x', 20)));
        Assert.Equal(3, result.DetailsJson!.Length);
    }

    [Fact]
    public void Negative_max_is_treated_as_zero_and_does_not_throw()
    {
        // A negative cap is nonsensical misconfiguration. Truncate must clamp to 0 rather than
        // throw, capping the value to the empty string (plus marker handling).
        var opts = new TruncatingAuditRedactorOptions { MaxDetailsJsonLength = -5, MaxTargetLength = -1, TruncationMarker = "" };
        var r = new TruncatingAuditRedactor(opts);
        var result = r.Apply(Evt(new string('x', 20), target: new string('y', 20)));
        Assert.Equal(string.Empty, result.DetailsJson);
        Assert.Equal(string.Empty, result.Target);
    }

    [Fact]
    public void Over_redact_fallback_scrubs_both_details_and_target_without_throwing()
    {
        // Drive the REAL TruncatingAuditRedactor.Apply into its catch branch via a reachable
        // misconfiguration (a null TruncationMarker faults inside Truncate). The over-redact
        // fallback must be strictly safer: BOTH DetailsJson AND Target scrubbed to null, no throw.
        var opts = new TruncatingAuditRedactorOptions { MaxDetailsJsonLength = 5, TruncationMarker = null! };
        var r = new TruncatingAuditRedactor(opts);
        var raw = Evt(new string('x', 50), target: "sensitive target");
        var result = r.Apply(raw);
        Assert.Null(result.DetailsJson);
        Assert.Null(result.Target);
    }
}
